A recording played in federal district court in Manhattan on Thursday suggests that race plays a factor in the city's stop and frisk practices. The tape captures a conversation between a patrol officer and his commanding officer. The commanding officer urges the officer to stop "the right people, at the right time, the right location," to prevent crime. The officer asks what the commander means by "right people" and he responds: "The problem, was what, male blacks and I told you at roll call and I have no problem telling you this, male blacks 14 to 20, 21." The tape was played on the fourth day of trial in a class action lawsuit that includes millions of stop and frisk incidents in New York City. Mayor Michael Bloomberg has championed stop and frisk as a method to prevent gun violence and reduce crime. The issue is playing prominently in the race to replace Bloomberg.